Inking units or dampening units of printing presses are employed for conveying an ink or a required dampening agent from appropriate supply devices to printing zone. Rollers or cylinders are provided in the inking unit or in the dampening unit for forming the required ink film or dampening agent film. The term roller and cylinder have the same meaning for understanding the present invention and will be used interchangeably. The rollers come into contact with each other along so-called roller strips. The ink film or the dampening agent film can be transferred in the roller strips from one roller to another roller.
Rollers, which are adjustably supported in a machine frame, are provided in such inking units or dampening units. A contact pressure in the roller strips can be changed by displacing these adjustably seated rollers with respect to the other rollers. An inking unit, with a distribution roller seated fixed in the frame and with a forme cylinder also seated fixed in the frame, is known from EP 0 826 501 A1. Inkis transferred from the distribution roller to the forme cylinder by use of an application roller that is arranged between the distribution roller and the forme cylinder. The application roller is itself adjustably seated in the machine frame and can be pressed, with an adjustable force, into the gap between the distribution roller and the forme cylinder. The device for seating the application roller is embodied in this prior device in such a way that the force with which the application roller is pressed into the gap between the distribution roller and the forme cylinder always acts along a bisecting line of an angle. In other words, although the size of the force for pressing the application roller can be changed, the direction of the force is unchangeably preset by the structural embodiment of the setting device. Thus, only the size of the contact pressure force can be changed for setting the contact pressure in the roller strips between the forme cylinder and the distribution roller on the one hand, and the application roller on the other hand. The resulting contact pressures in the roller strips ensue on the basis of the preset geometry.
A device for clamping bearing bushes of printing and forme cylinder bearing of a printing press is known from the Letters Patent DD 64 064. The device provides a hydraulic force for pressing the bearing bushes against the bore wall of the machine frame. The bearing bushes consist of two bushing sleeves shrunk on each other. Two hydraulically chargeable pressure chambers have been worked into the inner wall of the outer bearing bush, which pressure chambers are placed on both sides at 120° in respect to the resultant of the mean forces acting on the bearing. The true running properties of the cylinders are improved with this device, because a movement of the cylinders which is, to a large extent, vibration-free is achieved by the removal of the play which the bearing bushes have in the bore of the machine frame which receives them.
Letters Patent DE 15 61 014 C1 shows a roller bearing which is adjustable in only one direction, and which is used, in particular, for distribution and application rollers of inking units of printing presses. Setting assemblies, for adjusting the roller transversely in respect to its axis, are provided. The setting assemblies are arranged between a bearing journal connected with the frame wall and a housing, which housing receives one roller end and which is preferably embodied in a cup shape. The bearing journal and the housing are connected with each other by spring elements, which act oppositely to the setting assemblies. Here, the spring elements are preferably embodied as radially extending rubber bumpers, and the setting assemblies acting on the bearing journal are either embodied as a radially arranged setting screw, or as two setting screws arranged at 45°. In accordance with a further embodiment, the engagement or the disengagement of the roller, and therefore the adjustment of the roller bearing, can also take place by the use of two pressure chambers, which are diametrically arranged inside the housing and which can be acted on by air or a fluid, wherein the pressure chambers acting against each other are selectively charged with pressure.
A device for setting a contact pressure between rollers of a printing press is known from DE 100 01 582 A1. Hydraulic actuating elements, which are preferably embodied as double piston cylinders, are arranged between the adjoining rollers.
A device and a method for the semi-automatic setting of rollers is known from EP 0 958 918 A1. An adjustable first roller is placed against at least one second roller fixed in the frame. Spring-elastic elements charge the first roller with a spring-elastic force in the direction of the second roller.